The present invention falls in the field of locking devices in typewriters and particularly this invention relates to a carrier locking device used to render a movable print carrier fixed in a typewriter during periods when the typewriter is not in use for typing.
Modern typewriters being manufactured are increasingly of the kind having a horizontally fixed paper support platen in combination with a carrier unit which is power driven in a side to side motion traversing the platen. The carrier is usually supported by rollers or bearings to afford free and quick movement as in a gliding motion along parallel guide beams or rods. Carrier motion may be continuous or incremental and is accomplished by a motor driven system usually including a combination of tapes and pulleys or a rack and pinion gear arrangement. The carrier support and drive system in the prior art is known to be highly sensitive with respect to providing and maintaining precise control of carrier advancement, and once stopped, the carrier must be void of side play for accurately typing characters with proper spacing therebetween. This fact coupled with a high mass concentration found on most assembled carrier units are reasons for concern. For example, in the event of accidental side shock to the typewriter, which may particularly occur during shipping transport, the carrier unit together with its suspension and drive system need to be isolated from absorbing the full blunt force of a blow perpendicular to the carrier mounting arrangement. The purpose of isolating the carrier from side shock is to avoid the occurence of damaging results, such as, loss of critical carrier adjustments or even breakage of carrier support components causing the carrier to suddenly shift to one side of the typewriter out of control.